@article {Guerrero-Cruze01832-18,
author = {Guerrero-Cruz, Simon and Cremers, Geert and van Alen, Theo A. and Op den Camp, Huub J. M. and Jetten, Mike S. M. and Rasigraf, Olivia and Vaksmaa, Annika},
editor = {M{\"u}ller, Volker},
title = {Response of the Anaerobic Methanotroph {\textquotedblleft}Candidatus Methanoperedens nitroreducens{\textquotedblright} to Oxygen Stress},
volume = {84},
number = {24},
elocation-id = {e01832-18},
year = {2018},
doi = {10.1128/AEM.01832-18},
publisher = {American Society for Microbiology Journals},
abstract = {{\textquotedblleft}Candidatus Methanoperedens nitroreducens{\textquotedblright} is an archaeon that couples the anaerobic oxidation of methane to nitrate reduction. In natural and man-made ecosystems, this archaeon is often found at oxic-anoxic interfaces where nitrate, the product of aerobic nitrification, cooccurs with methane produced by methanogens. As such, populations of {\textquotedblleft}Ca. Methanoperedens nitroreducens{\textquotedblright} could be prone to regular oxygen exposure. Here, we investigated the effect of 5\% (vol/vol) oxygen exposure in batch activity assays on a {\textquotedblleft}Ca. Methanoperedens nitroreducens{\textquotedblright} culture, enriched from an Italian paddy field. Metagenome sequencing of the DNA extracted from the enrichment culture revealed that 83\% of 16S rRNA gene reads were assigned to a novel strain, {\textquotedblleft}Candidatus Methanoperedens nitroreducens Verserenetto.{\textquotedblright} RNA was extracted, and metatranscriptome sequencing upon oxygen exposure revealed that the active community changed, most notably in the appearance of aerobic methanotrophs. The gene expression of {\textquotedblleft}Ca. Methanoperedens nitroreducens{\textquotedblright} revealed that the key genes encoding enzymes of the methane oxidation and nitrate reduction pathways were downregulated. In contrast to this, we identified upregulation of glutaredoxin, thioredoxin family/like proteins, rubrerythrins, peroxiredoxins, peroxidase, alkyl hydroperoxidase, type A flavoproteins, FeS cluster assembly protein, and cysteine desulfurases, indicating the genomic potential of {\textquotedblleft}Ca. Methanoperedens nitroreducens Verserenetto{\textquotedblright} to counteract the oxidative damage and adapt in environments where they might be exposed to regular oxygen intrusion.IMPORTANCE {\textquotedblleft}Candidatus Methanoperedens nitroreducens{\textquotedblright} is an anaerobic archaeon which couples the reduction of nitrate to the oxidation of methane. This microorganism is present in a wide range of aquatic environments and man-made ecosystems, such as paddy fields and wastewater treatment systems. In such environments, these archaea may experience regular oxygen exposure. However, {\textquotedblleft}Ca. Methanoperedens nitroreducens{\textquotedblright} is able to thrive under such conditions and could be applied for the simultaneous removal of dissolved methane and nitrogenous pollutants in oxygen-limited systems. To understand what machinery {\textquotedblleft}Ca. Methanoperedens nitroreducens{\textquotedblright} possesses to counteract the oxidative stress and survive, we characterized the response to oxygen exposure using a multi-omics approach.},
issn = {0099-2240},
URL = {https://aem.asm.org/content/84/24/e01832-18},
eprint = {https://aem.asm.org/content/84/24/e01832-18.full.pdf},
journal = {Applied and Environmental Microbiology}
}